Fire Debris Analysis

By The Forensic Experts Group

ARE THERE IGNITABLE LIQUID RESIDUES IN THE DEBRIS?

Fires are energetic events with the potential to cause massive destruction to life and property. Most fire investigations are associated with suspected arson, insurance claims and industrial accidents (i.e. shipyard fires, chemical storage site fires).

A frequent request by fire investigators of suspicious fire scenes is the analysis of fire debris for the presence of ignitable liquid residues (ILRs). Ignitable liquids are used as accelerants by arsonists to initiate a fire and to increase its rate of growth and spread. Common accelerants include petroleum-based products such as petrol, diesel, kerosene, mineral turpentine and commonly available solvents such as thinners and specialty solvents.

COLLECTION & SUBMISSION OF EVIDENCE

Fire debris is collected in air-tight, unlined metal tins or in Kapak or Nylon bags. Occasionally, partially burnt bottles containing small amounts of suspicious liquids, and gas samples in gas sampling bags are also submitted for examination.

HOW IS THE EVIDENCE EXAMINED IN THE LABORATORY?

Fire debris evidence that is submitted to TFEG is analysed according to widely accepted ASTM Standard Test Methods, under rigorous internal quality assurance standards. The typical steps in fire debris analysis are depicted in Figure 2.

Preliminary examination: The nature of the debris (e.g. plastic, paper materials), and presence of other physical evidence (e.g. fingerprints and DNA on a Molotov cocktail) are identified in order to determine the proper sequence of examination to maximize evidence (e.g. to examine for DNA or ILRs first).

Extraction: This process separates and pre-concentrates ILRs from the fire debris.

Analysis: Volatile chemical compounds in the extracts are separated and identified by the analytical instruments.

Interpretation of results: The chemical fingerprints of the compounds are analysed to determine the presence or absence of ignitable liquid residues.

Report writing: The report describes the examinations conducted, the results and conclusions, with appropriate qualifiers. Each report is peer-reviewed by an experienced scientist. The reporting scientist will provide expert court testimony when required.

“Fire debris analysis is a specialty of fire investigation and forensic sciences that is based on objective science and subjective evaluation. Objective science is used in the analytical scheme until chromatographic or mass chromatographic data are generated. Then comes the most difficult part of the analysis: the interpretation of results.”

– Eric Stauffer, Julia A. Dolan and Reta Newman

WHY THE FORENSIC EXPERTS GROUP?

You can have confidence when you submit the evidence to TFEG. We are in close proximity to you, meaning that you have easy access, and no longer need to incur additional costs and time to courier your evidence overseas. If you are a fire investigator looking for a reliable laboratory to perform chemical testing for your fire debris, or a collaborator to partner you in your investigations, look no further.

Our accomplished scientists have more than 15 years of experience in fire debris analysis and are well recognized by the Singapore courts in providing expert testimony in Court. Having worked on thousands of cases, including many high-profile ones, they are well-versed with the challenges in fire debris analysis and are able to sieve through the challenging background “noise” to provide an accurate and reliable interpretation of the findings. The significance of the findings are explained clearly in the report and to the client so that readers of the report are not misled by a positive or negative finding.

To find out more about the chemistry of fires and the challenges in fire debris analysis, look out for our article “Fire and Explosion” featured in the February 2016 issue of the Singapore Law Gazette.